1. Field of the Invention
This invention relates in general to computer-implemented database systems, and, in particular, to a technique for deferring dataset creation to improve system manageability for a database system.
2. Description of Related Art
Databases are computerized information storage and retrieval systems. A Relational Database Management System (RDBMS) is a database management system (DBMS) which uses relational techniques for storing and retrieving data. Relational databases are organized into tables which consist of rows and columns of data. The rows are formally called tuples or records. A database will typically have many tables and each table will typically have multiple tuples and multiple columns. The tables are typically stored on direct access storage devices (DASD), such as magnetic or optical disk drives for semi-permanent storage. An index is a type of table that is used to access data in a table holding data to be accessed (e.g., employee data). To distinguish between an index or a table holding data to be accessed, a table holding data to be accessed will be referred to as a xe2x80x9cdata tablexe2x80x9d. Both data tables and indexes are types of database objects that may be stored in a database.
There are many different application programs (i.e., computer programs) that use databases. An application system is one that supports many application programs on a single relational database system. Each of the supported application programs requires one or more data tables and indexes. When the application system is started, it typically creates all needed data tables and indexes in the database system for each of the supported application programs. For example, if an application system supported 3 application programs (a Human Resources application program, a Finance application program, and a Manufacturing application program) and each application program required 10,000 data tables and indexes, then the application system would create 30,000 data tables and indexes.
An Enterprise Resource Planning (ERP) system is a business management system that integrates various facets of a business, such as, human resources, finances, and manufacturing. Software systems have been developed to implement ERP systems. For example, an application system that supports various application programs (a Human Resources application program, a Finance application program, and a Manufacturing application program) may be an ERP system.
A typical ERP system may use a database that typically contains several thousand data tables and indexes. For customers that enable a few application programs on the ERP system (out of many available application programs), a major portion of the data tables and indexes are empty (i.e., the data tables and indexes for the application programs that are not enabled). For example, if a customer enabled a Manufacturing application program, without enabling the Human Resources application program or the Finance application program, the database would still be created with 30,000 data tables and indexes, which would include the 20,000 data tables and indexes for the Human Resources application program and the Finance application program, which are not needed.
Customers have no knowledge of which data tables and indexes are in-use or not in-use. Customers will still need to pay the database/storage administration (e.g. backup/recovery, DASD utilization, etc.) overheads for all data tables and indexes in the ERP system. In addition, during the ERP system installation/migration/upgrade process, all customers will need to suffer the long elapsed time delay to create/delete the underlying datasets for all data tables and indexes. The dataset creation process is the process of allocating storage from, for example, DASD. In general, the dataset creation process is a slow process. For example, it takes approximately 0.1-0.3 seconds to create a single dataset in the IBM S/390(copyright) system.
Therefore, there is a need in the art for an efficient technique for creating a database system that saves time and storage space.
To overcome the limitations in the prior art described above, and to overcome other limitations that will become apparent upon reading and understanding the present specification, the invention discloses a method, apparatus, and article of manufacture for a computer-implemented technique for deferring dataset creation to improve system manageability for a database system.
In accordance with the invention, database objects are created at a computer connected to a data storage device. Initially, a command to create a database object is received. A database object definition for that database object is recorded. When the database object is accessed, a dataset for the database object is created from its database object definition.